The invention relates in general to a seal pulling and removing tool and more particularly to a tool and accessory for pulling and removing ring-shaped seals from, for example, an automobile transmission housing.
Very often, when automobile transmissions are being repaired, it is necessary to remove the ring-shaped seal which provides the fluid seal between the transmission drive shaft and the transmission housing. Generally, the transmission seal comprises an annular metallic housing formed from relatively thin sheet metal and having a circumferential inwardly turned flange. A resilient, elastomeric ring seal member circumscribes the flange and provides fluid confinement as well as protection to the internal parts of the transmission from dirt and other dilaterious substances.
When removing seals of this type, it is necessary to firmly engage the inner surface of the inwardly turned housing flange and exert a force on the housing in a direction substantially along the axis of the transmission shaft. That is not an easy task because the seals are initially engaged with an interference fit, and further after years of use, tend to become corroded and even more difficult to remove. Also, it is necessary for the mechanic to work under the automobile and within the confines of the chassis, whether the automobile is raised or lowered, as such it is difficult for the mechanic to fine room to work or to get proper leverage for pulling the seals.
Tools of the prior art for pulling ring-shaped seals have not been entirely successful. Prior art tools have generally included an elongate member attachable to a slide hammer or the like, with said member having a hook shaped portion at one end. The hook portion is relatively narrow with a pointed hook tip or a narrow hook end surface. In order to initially engage such a tool, it is necessary to insert the hook between the shaft and the seal flange with the hook disposed 90.degree. from its normal operating position. That is to say, the tool must be turned so that the hook is disposed generally tangential to the shaft wherein it may pass through the space between the seal and the shaft interiorly of the seal housing. Once inserted, the hook must then be rotated 90.degree. to a generally radial position to bring the hook into engagement with the inner surface of the inwardly turned flange. Because the hook portion must be relatively thin to pass between the shaft and the inwardly turned flange, these prior art tools produce localized, high unit stress which tend to rupture the metal seal. All too often fragments of metal, rubber or of the retention spring can fall into the transmission, causing problems in the future due to fouling of the transmission pump or fluid lines. Prior tools are also difficult to use because they do not provide secure engagement with the seal and are inflexible and not adjustable so as to adapt to the particular work position required of the mechanic.
It is therefore a general object of the present invention to provide a new and improved tool for pulling and removing ring-shaped seals from, for example, the transmission housing of an automobile. It is a more particular object of the present invention to provide a seal pulling tool having a hook shaped portion at one end with the hook portion having a relatively broad end face surface to distribute the load and prevent the hook from rupturing the seal housing.
It is a still more particular object of the present invention to provide such a seal pulling tool wherein the hook shaped portion is pivotal to allow the hook to wrap around the seal flange to make a borad end surface contact and secure engagement with the seal possible.
It is a more particular object of the present invention to provide such a seal pulling tool wherein the hook end portion as provided by a plurality of articulated segments which will conform to the arcuate shape of the seal or the shaft thereby assisting initial position of the tool and providing firm and secure engagement between the hook and the seal.
It is a further object of the present invention to provide a tool accessory which may be applied to a common tool shaft to provide an improved seal pulling tool.
The embodiment of the invention illustrated and to be described provides a tool for pulling and removing ring-shaped seals from an automobile transmission housing or the like. The tool contemplated comprises an elongated main or handle section having first and second ends, grip means at said first end affording holding of the tool by an operator, and an end member pivotally mounted to a second end. The end member may be carried by a section of the tool integral with the main section, or as will be described with respect to the drawings, the end member may be part of an accessory mountable to an elongate main or handle section. In either arrangement the end member includes a hook means at one end thereof, with said end member adapted to pivot with respect to the main or handle section from a first position substantially transverse to the main section to a second position substantially in line with the main section. The pivotal movement of the end member afforded by the present invention provides means by which hook means having a substantial width may engage the seal when the end member is in the first position and wrap around the seal as the end member is pivoted from the first position to the second position. The end member is then locked in said second position, such that upon the application of an impact to the main or handle section, a force will be transmitted to the seal in a direction tending to unseat the seal housing.
As to the tool accessory mentioned above and adapted to be mounted at the end of an elongated shaft or handle extension to provide the overall tool construction, said tool accessory includes a bifurcated fitting adapted to be mounted to the shaft extension and having a pair of spaced apart arms or extensions with the pivotally mounted end member carried between the extensions. The pivotal end member of either contemplated arrangement, advantageously may be fabricated from a plurality of similar shaped segments, with relative movement poovided between certain of the segments to facilitate use and positioning of the took, as will be explained more fully hereinafter.